Disulfiram and copper form active complexes that have been shown to be effective in vitro in killing neoplastic cells of various cancers, see, e.g., U.S. Pat. Nos. 6,548,540; 6,589,987; and 7,816,403, and that have been shown to significantly augment temozolomide activity against patient-derived glioma cells from both newly diagnosed and recurrent tumors, both in vitro and in animal models, see Lun et al., Clin. Cancer Res. 22(15):3860-75 (2016). Disulfiram and zinc also form active complexes that kill neoplastic cells in vitro, see, e.g., U.S. Pat. No. 6,548,540. Despite this promise, however, combination therapy with disulfiram and copper and disulfiram and zinc has not yet been proven to be effective in human cancer patients. There is a continuing need for methods, compositions, and dosage forms that allow the preclinical efficacy of combination therapy with disulfiram and copper, and disulfiram and zinc, to be translated into effective human therapies.